Your Guide to Idaho Window Tint Laws
Idaho's window tint rules all live in one short statute, Idaho Code 49-944. Here is what it allows on each window, in plain English, from the Caldwell shop that tints cars and trucks for drivers across the Treasure Valley.
The Short Answer
In Idaho, the front side windows and the back glass must let in at least 35% of light, and the side windows behind the driver at least 20%, each with a ±3% tolerance. No window film may be more than 35% reflective. On the windshield, non-reflective tint is allowed only above the AS-1 line. Film darker than 20%, such as 5% limo tint, is illegal on every window, even with a medical exemption.
Last reviewed September 2026 against Idaho Code 49-944.
Idaho Tint Limits by Window
VLT (visible light transmission) is the share of light that gets through the window. The lower the number, the darker the tint: 35% lets in about a third of the light, while 5% "limo" tint lets in almost none. Idaho uses the same limits for every motor vehicle, whether it's a car, truck, SUV or van.
| Window | Darkest legal tint | Max. reflectance |
|---|---|---|
| Windshield | Above the AS-1 line only | Non-reflective |
| Front side windows and vents | 35% VLT ±3% | 35% ±3% |
| Side windows behind the driver | 20% VLT ±3% | 35% ±3% |
| Back glass (rear window) | 35% VLT ±3% | 35% ±3% |
With a physician's letter under the medical exemption: 70% VLT on the whole windshield and 20% on every other window. Factory privacy glass is exempt.
The ±3% tolerance means a front window that meters 32% still passes. Officers check with a tint meter, which reads the glass and the film together, and factory glass isn't perfectly clear on its own, so a film labeled 35% can meter a little lower once it's installed. We help you choose a shade that stays legal on your vehicle's glass before anything goes on.
Windshield Tint and the AS-1 Line
Most windshields have a small "AS-1" mark on the glass near the top corners. A line across the windshield at that mark is the AS-1 line. Idaho allows non-reflective film above it and nothing below it. Only if your windshield has no identifiable AS-1 line does the fallback apply: film may then cover the top 6 inches of the exposed glass.
A visor strip that stays above the line can be any shade, as long as it isn't reflective. Film on the rest of the windshield is allowed only under the medical exemption, and then it must let in at least 70% of light.
Factory Privacy Glass Is Legal
Many trucks, SUVs and vans leave the factory with dark privacy glass behind the driver. Idaho Code 49-944(5) exempts glass the vehicle was sold with when new, or could have been ordered with from the manufacturer or an authorized dealer, so that glass is legal even if it meters darker than 20%. The exemption covers the glass as the vehicle was sold. Film added later still has to meet the limits above.
Medical Exemption: How It Works
- Get it in writing from a physician. Idaho's exemption needs written verification from a licensed physician that the driver or a passenger must be protected from sunlight or heat for medical reasons tied to past or current treatment.
- Keep the letter in the vehicle. The law requires it to be carried there. The exemption applies while the vehicle is driven by, or carrying, the person the letter covers.
- Stay within the medical limits. At least 70% VLT on the front windshield and at least 20% on every other window, each ±3%, and no more than 35% reflective.
The statute doesn't call for a state permit or window sticker; the physician's letter is the paperwork. It also names a licensed physician, and unlike Oregon's law it doesn't mention optometrists.
What Happens if You Get a Tint Ticket?
Illegal tint is an infraction under Idaho Code 49-944(6). An infraction is a civil public offense, not a crime: there's no jail and no jury trial. The penalty is the amount in the Idaho Supreme Court's infraction penalty schedule, plus court costs, and the judgment is reported to the Idaho Transportation Department. Because illegal tint breaks a state equipment law, an officer who reasonably believes your windows are too dark can pull you over for it.
The same statute makes it illegal to sell, or offer to sell, a vehicle whose tint doesn't comply, so it's worth checking before you buy or sell a used car or truck.
The 808 Customs Ticket Insurance Promise
If you get a fix-it ticket for a tint we installed, our Ticket Insurance has you covered. We will remove the tint from the front doors so you can clear the ticket. Afterward, return to our shop, and we will reinstall the same shade, or a legal shade of the same film for you, absolutely free. This service is included with our Carbon and Ceramic packages and covers you for one incident within the first full year.
Planning new tint? See our car and truck window tinting options or get a quote for your vehicle.
Other Idaho Tint Rules
- Reflectance: Film on the side windows and back glass may be no more than 35% reflective (±3%), and windshield film must be non-reflective.
- Colors: Idaho's tint law doesn't restrict film colors.
- Side mirrors: Idaho doesn't tie mirrors to tint. Its mirror law (Idaho Code 49-940) requires a mirror on each side only when a load, a trailer or the vehicle's construction blocks the view straight back.
- Crossing into Oregon: Oregon's limits differ; see our Oregon tint law guide.
Idaho Tint Law Questions
This guide explains Idaho Code 49-944 for general information, as last reviewed in September 2026. It is not legal advice. If you need legal advice, please consult an attorney.